Field of the Invention
The present invention relates to a recording material processing apparatus that performs offset processing on recording materials and an image forming apparatus provided with the recording material processing apparatus.
Description of the Related Art
Among image forming apparatuses, there is an image forming apparatus which has a recording material processing apparatus capable of performing offset processing on a recording material and discharging the recording material. Such a recording material processing apparatus receives and stacks a recording material on which an image has been formed, bundles one or more stacked recording materials into a single bundle using an alignment member, and discharges the bundled recording materials by shifting each bundle. Japanese Patent Laid-Open No. 2013-230891 discloses an arrangement in which offset processing is performed by two alignment members having different driving sources. Japanese Patent Laid-Open No. 2000-143082 also discloses an arrangement in which offset processing is performed by shifting a bundle after aligning the recording materials by an alignment member.
The cost of the arrangement of the Japanese Patent Laid-Open No. 2013-230891 increases since a driving source is provided in each of the two alignment members. The throughput decreases in an arrangement in which the bundle is shifted after aligning the recording materials by the alignment members since it becomes necessary to create an interval between the recording materials for each bundle shift operation. Although Japanese Patent Laid-Open No. 2000-143082 discloses a buffer roller provided to prevent this decrease in throughput, the cost increases due to the provision of the buffer roller.